No abstract

No abstract

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A method is set forth for the computation of test-section, aftershock, and stagnation conditions in hotshot tunnels of Arnold Engineering Development Center, using nitrogen at stagnation temperatures from 1500 to 5000 o K. The basic input data are the stagnation pressure in the res2rvoir, the pitot pressure be~ind a normal shock, and the heat-tran.-3fer rate at the stagnation point. The value of the overall enthalpy is adjusted by numerical iteration until the measured and computed heat-transfer rates are numerically equal within a prescribed tolerance. PUBLICATION REVIEW This report has been reviewed and publication is approved.

This study of the velocity of sound in air involves the use of the magnetostriction oscillator in an experiment similar to those of G. W. Pierce and others, who used piezoelectric crystals as sources of sound. The wave system generated by the source is investigated by observing the reactions of the source when the sound waves are reflected back upon it from a moveable reflector. The range of frequencies used extends from 20,000 to 70,000. The irregularities of the wave system near the source are studied in some detail. It is found that these irregularities vary with the frequency, as well as with the diameters of both the source and the reflector, and that they vanish at relatively large distances from the source. The values of the velocityof sound then obtained show no variations with respect to the frequency.